 /*******************************************************************************
  * Copyright (c) 2000, 2004 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.texteditor.quickdiff.compare.rangedifferencer;

 import java.util.ArrayList ;
 import java.util.List ;

 /**
  * A custom iterator to iterate over a List of <code>RangeDifferences</code>.
  * It is used internally by the <code>RangeDifferencer</code>.
  *
  * @since 3.0
  */
 /* package */ class DifferencesIterator {

     List fRange;
     int fIndex;
     RangeDifference[] fArray;
     RangeDifference fDifference;
     
     /**
      * Creates a differences iterator on an array of <code>RangeDifference</code>s.
      */
     DifferencesIterator(RangeDifference[] differenceRanges) {
         
         fArray= differenceRanges;
         fIndex= 0;
         fRange= new ArrayList ();
         if (fIndex < fArray.length)
             fDifference= fArray[fIndex++];
         else
             fDifference= null;
     }

     /**
       * Returns the number of RangeDifferences
       */
     int getCount() {
         return fRange.size();
     }

     /**
      * Appends the edit to its list and moves to the next <code>RangeDifference</code>.
      */
     void next() {
         fRange.add(fDifference);
         if (fDifference != null) {
             if (fIndex < fArray.length)
                 fDifference= fArray[fIndex++];
             else
                 fDifference= null;
         }
     }

     /**
      * Difference iterators are used in pairs.
      * This method returns the other iterator.
      */
     DifferencesIterator other(DifferencesIterator right, DifferencesIterator left) {
         if (this == right)
             return left;
         return right;
     }

     /**
       * Removes all <code>RangeDifference</code>s
       */
     void removeAll() {
         fRange.clear();
     }
 }

